Effect of supplemental ascorbic acid on T3-induced heart failure syndrome and metabolic parameters of broiler chickensHassanzadeh, M1; Buyse, J2 & Decuypere, E.2
1Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, IRAN.
2Laboratory for Physiology and Immunology of Domestic Animals, K.U.Leuven. Kasteelpark Arenberg 30,, B-
3001 Heverlee, Belgium.; E.Mail:
A total of 420 male broiler chickens were randomly divided and fed a basal diet with or without 1.5 ppm T3 from day 1 (1) and with or without 500 ppm vitamin C added to the diet. All birds had ad libitum access to feed and water but the light and temperature programs were provided as standard. During the study, the incidence of right ventricular failure and ascites, body weight, feed intake, feed conversion ratios, haematocrit, plasma T3 and T4 levels were determined (2).
Dietary T3 markedly increased heart failure and ascites. The incidence of ascites was clearly reduced (60 %) by the effect of 500 ppm vitamin C supplementation in the T3 and control groups. Broiler chickens that received ascorbic acid without T3 showed a tendency for higher body weight and lower feed conversion ratios compared to those birds fed without ascorbic acid (Table 1). The influence of T3 and ascorbic acid on haematocrit value was not significant but those birds fed diet with ascorbic acid showed a tendency for lower haematocrit values. Dietary T3 supplementation significantly increased plasma T3 levels (P<0.0001) and decreased T4 levels (P<0.0001). Ascorbic acid significantly decreased plasma T3 concentrations in birds fed a T3 supplemented diet (P<0.0001) but not in control birds while plasma T4 levels were higher in birds received ascorbic acid in the diet compared to those fed a control diet (P<0.0001).
There are several studies describing that ascorbic acid has a beneficial effect on heart failure syndrome and ascites by scavenging on the oxygen-derived free radicals (3) but in present study most remarkably ascorbic acid declined ascites incidence by reducing of hyperthyroidism and as a consequence the metabolic disorders. This finding confirms the earlier report when broiler chickens were reared in low environmental temperature (2).
1- Decuypere et al., (1994), British Poultry Science,35, 287-297;
2-Hassanzadeh et al.,(1997), Avian Pathology, 26,33-44;
3-Bottje & Wideman (1995) Poultry and Avian Biology Reviews, 6, 221-231.
Table 1: The number of heart failure and ascitic chickens, body weight, feed intake, feed conversion ratios, haematocrit values, plasma T3 and T4 levels in broiler chickens given a control (Co) or a T3 supplemented diet (T3) with (As) or without 500 ppm ascorbic acid.
Parameters/treatment NCo AsCo NT3 AsT3 P- value
Heart failure, Body weight (g), Feed intake (G), Feed conversion, Haematocrit (%)
2002 ± 24a
3636 ± 34a
29 ± 0.4ab
2.5 ± 0.2c
13 ± 0.8a
2046 ± 20ab
3543 ± 42a
1.73 ± 001b
28 ± 0.3b
2.6 ± 0.2c
10 ± 0.8b
1604 ± 40b
3103 ± 39 b
1.94 ± 0.02a
31 ± 0.5a
7.2 ± 0.5a
1.5 ± 0.1c
1601 ± 21b
3136 ± 59b
1.95 ± 0.06a
30 ± 0.4ab
4.6 ± 0.5b
1.5 ± 0.1c
The influence of an increased cobalt supply on microbial vitamin B12 synthesis in the rumen of dairy cowsKirsten Stemme1, P. Lebzien2, G. Flachowsky2, H. Scholz3
1Institute of Animal Nutrition, School of Veterinary Medicine, Hanover
2Institute of Animal Nutrition, Federal Agricultural Research Centre, Brunswick
3 Clinic for Cattle Diseases, School of Veterinary Medicine, Hanover
In contrast to most mammals, ruminants are not dependent on a dietary vitamin B12 supply, because micro-organisms in the forestomachs of ruminants can use cobalt to synthesize vitamin B12 in amounts meeting ruminants requirements. As it is known from the literature that the extent of microbial vitamin B12 synthesis depends on the amount of cobalt (Co) provided with the ration (SMITH and MARSTON, 1970), the following investigations were designed to test the effect of an elevated dietary Co supply on the amount of vitamin B12 reaching the duodenum.
5 lactating cows (German Holstein, av. body weight 678 ± 45 kg, av. milk yield 19.6 ± 3.7 kg) with a ruminal cannula and a T-cannula in the proximal duodenum were allotted to an incomplete cross-over. They were fed a ration of wilted grass-silage (10 kg DM), 1 kg balancing concentrate with or without cobalt supplement and additionally 3 kg dairy concentrate (ration: in DM 23.7% crude fiber, 21.5 % crude protein). With the exception of cobalt, minerals were fed according to the GfE in both groups. The experiment comprised 2 periods of 21 days each, in which subsequently the unsupplemented or the supplemented ration was fed. After 14 days of adaptation the duodenal chyme was sampled applying a method published by ROHR et al. (1979). The cobalt concentrations in feedstuffs and digesta were analysed using the ICP-technique (ICP-OES; Fa. Spectro); vitamin B12 concentrations in the digesta were determined by ELISA (RIDASCREEN® Vitamin B12).
In the supplemented ration a cobalt content of 0.29 mg/kg DM was analysed in comparison to the unsupplemented one (Co content of 0.17 mg/kg DM). Results show significantly higher amounts of vitamin B12 reaching the duodenum for the supplemented group (8.63 ± 2.22 mg vitamin B12/day) as compared to the controls (3.67 ± 0.69 mg vitamin B12/day), although the individual levels vary considerably.
Feeding 0.29 mg Co/kg DM resulted in higher amounts of vitamin B12 in the duodenal digesta. But further research is nessesary to study if this affects the vitamin B12 concentration in the serum, liver and milk of cows in any way.
GfE (Gesellschaft für Ernährungsphysiologie) 2001:
Empfehlungen zur Energie- und Nährstoffversorgung der Milchkühe und Aufzuchtrinder. DLG-Verlag, Frankfurt/Main Rohr, K.; Brandt, M.; Castrillo, O.; Lebzien, P.; Assmus, G., 1979.
Landbauforschung Völkenrode 29, 32-40; Smith. R.M., Marston, H.R.,1970. Br. J. Nutr. 24, 857-877
The study was supported by a grant from the H. WILHELM SCHAUMANN FOUNDATION
The effect of cobalt supply to pregnant cows on the vitamin B12 status of their calvesKirsten Stemme1, U. Meyer2, G. Flachowsky2, H. Scholz3
1Institute of Animal Nutrition, School of Veterinary Medicine, Hanover
2Institute of Animal Nutrition, Federal Agricultural Research Centre, Brunswick
3 Clinic for Cattle Diseases, School of Veterinary Medicine, Hanover
Ruminants are able to synthesize vitamin B12 in their forestomachs, but preruminant calves are dependent on a dietary supply. Because of indications from the literature that dietary cobalt increases vitamin B12 concentration in ewes colostrum and that there is an increase of vitamin B12 in lambs serum after ingestion of colostrum (HALPIN and CAPLE, 1982), the following investigation with dairy cows and their calves was designed to test the influence of oral cobalt supply to cows on the vitamin B12 status of the calves.
The experiment was conducted with a total of 20 lactating dairy cows of the German Holstein breed. The average milk yield amounted to 32.5 kg FCM at the start of the experiment (70th day of lactation), which lasted 280 days. 10 animals each were allotted to the following cobalt treatments: Group 1: without Co supplementation (0.13 mg Co/kg DM in the ration » near to the recommended requirement) Group 2: with an extra oral Co supply (0.27 mg Co/kg DM in the ration) Milk yield was recorded daily and milk composition twice a week. Milk samples for vitamin B12 analysis (chemilumineszenz) were taken at the beginning of the experiment, before drying off (day 220) and on the day of calving. Additionally, venous blood samples of calves were taken directly after birth and on the following 4 days for vitamin B12 determination in the serum.
Vitamin B12 concentrations in the colostrum were detected to be 4 to 6 times higher as compared to milk. Colostrum showed a tendency towards a higher vitamin B12 concentration (21.0 ± 8.4 versus 16.7 ± 11.9 ng/ml) due to cobalt supplementation, but the results failed to reach significance. Dietary cobalt levels did not affect vitamin B12 concentration in milk. Only a marginal increase was detected in the course of lactation from 3.77 ± 0.96 to 4.75 ± 3.05 ng vitamin B12/ml for controls and from 3.66 ± 1.03 to 4.44 ± 0.96 ng vitamin B12/ml for the supplemented cows. Differences in milk yield and milk composition (fat, protein and lactose) due to cobalt supplementation were not detected. Extra cobalt supplementation to the ration of pregnant cows did not result in increased vitamin B12 levels in the serum of their calves before they received colostrum. After the intake of colostrum the vitamin B12 concentration in the serum of calves increased in both groups (342 ± 162 versus 361 ± 186 pg/ml) and decreased afterwards.
From the results it can be concluded that a cobalt content of 0.27 mg Co/kg DM in the ration of pregnant cows (higher than the recommended allowance of 0.10 mg/kg DM) does not effect the vitamin B12 status of their calves.
Halpin, C.G., Caple, I.W., 1982. Proc. Austr. Soc. Anim. Prod., 14: 658 The study was supported by a grant from the H. WILHELM SCHAUMANN FOUNDATION
Individual variation in pre-hibernation polyunsaturated fatty acid intake and its effect on over-winter survival by golden-mantled ground squirrels, Spermophilus lateralisWendy R. Hood1,2* and Craig L. Frank1;
1Louis Calder Center, Fordham University, Armonk, NY 10504
2Current address: Coastal Carolina University, Conway, SC 29528
The results of several controlled laboratory studies suggest that use, depth, and duration of torpor bouts in the golden-mantled ground squirrel (Spermophilus lateralis) are influenced by the intake of polyunsaturated fatty acids (PUFAs). However, it remains unclear if these nutritional limitations are similar for free-ranging animals. The goals of the study were as follows: 1) describe individual patterns of body condition and intake of PUFAs during the fattening period, 2) describe patterns of crude lipid and PUFA composition of plant species consumed by ground squirrels, and 3) determine if there are correlations between body condition, intake of PUFA, and over-winter survival. Animals were trapped in the White Mountains of California throughout the active season. Body condition was determined using TOBEC and blood samples were collected to determine plasma levels of PUFAs. Diet was determined by fecal analysis and behavioral observation. Plants matching those found in the diet were collected to determine fat and fatty acid composition. Lean mass of ground squirrels remained constant during the fattening period but body mass and percent body fat increased, with both lean mass and percent body fat varying between individual squirrels. Variation in body mass among juveniles was substantial, with the body mass of juvenile females being greater than that of juvenile males. Linoleic (18:2) and _-linolenic acid (18:3) were the primary PUFAs identified in plasma samples. There was a small but significant reduction in intake of 18:2 (40.9+1.9%) by adults just prior to the onset of hibernation. Circulating levels of 18:3 (4.3+0.9%) was low in most cases and absent from the plasma of all adults remaining active into September. 18:2 (44.1+6.9%) was the predominate PUFA consumed by juveniles, whereas 18:3 (0.9+0.6%) was largely absent from the diet that continue to fatten into September. These trends were not surprising since 18:2 is most abundant in seeds that were available throughout the sampling period, whereas 18:3 is an important component of chlorophyll and thus is expected to be largely unavailable in late summer and early fall as plants senesce. Intake of both 18:2 and 18:3 was greater for adult females than males, which may be associated the reduced time available for fattening in females. There were no gender differences in plasma PUFAs for juveniles. There were no significant differences in plasma PUFAs between individuals, thus any affect of PUFA intake on over-winter survival will more likely be associated with net accumulation of PUFAs and total body fat rather than concentration of PUFAs consumed. The relative concentrations of 18:2 and 18:3 in the plant most commonly consumed by ground squirrels, Ivesia lycopodioides, differed substantially from the relative concentrations of these fatty acids in ground squirrel plasma. Squirrels largely select for the reproductive structures of the plants, which had greater concentrations of crude lipid (7.9+5.3% DM) and both 18:2 (6.3+3.2 mg/g lipid) and 18:3 (11.7+5.3 mg/g lipid) than leaves and stems. Concentrations of 18:3 were greater than 18:2 for all parts of the plant examined, whereas concentrations of plasma 18:2 were much greater than that of 18:3. These results suggest notable intake of other items with much higher concentrations of 18:2 and lower 18:3 or plasma concentrations of 18:2 and 18:3 do not directly reflect the proportions of these PUFAs in the diet. The effect to PUFA intake over-winter survival was determined in June 2002 and will be discussed at the Symposium.
Effect of a sub-maintenance, low-fat diet on body composition in Steller sea lionsD.A.S. Rosen, A.W. Trites
Marine Mammal Research Unit, University of British Columbia, Vancouver, Canada
The decline of Steller sea lions (Eumetopias jubatus) in Alaska may be linked to an increased reliance on prey with low fat content, and/or periodic inadequate food intake. However, no studies have documented the effects of a sub-maintenance, low-fat diet on sea lion health or condition (percent body fat). We tested whether a sub-maintenance, low-fat diet of Atka mackerel induced greater decreases in body condition compared to a high-fat herring diet. Two juvenile female Steller sea lions (4 years old) were alternately maintained on isocaloric (total net energy/day) diets of Atka mackerel or herring. The animals were fed a submaintenance amount of fish, sufficient to lose a maximum of 15% of initial body mass over the 30 d trial period. As predicted for isocaloric diets, although substantial changes in body mass occurred (-9.8±2.1%) there were no differences due to food type. However, total body lipids decreased an average of 6.0 kg while on an Atka mackerel diet versus 1.0 kg while eating herring. Correspondingly, lipid loss accounted for a greater proportion of the total mass loss when fed a diet of Atka mackerel (43%) than when fed herring (10%). Certain blood parameters changed in a predictable fashion when the animals were losing body mass, and some only changed on one of the diets. These parameters may prove useful for judging the nutritional status of wild sea lions. The preliminary results of our experiment indicate that a low-fat diet may compound the impact of low food availability on sea lion health.
Do cats need arachidonic acid in the diet for reproduction?James G. Morris
Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis. CA USA.
There is debate whether cats need arachidonic acid (AA) in the diet for reproduction. Rivers et al. (1975) suggested that cats could not convert linoleic acid (LA) to AA, and cats and lions lacked a Ä6 desaturase. Sinclair et al. (1981) showed the presence of 20:3n-9 in the plasma of cats given an essential fatty acid-deficient (EFA-deficient) diet based on hydrogenated beef fat (HBF) and suggested an alternate pathway for AA synthesis using Ä5 and Ä8 desaturases. MacDonald et al. (1983) also reported that cats given HBF diet had low concentrations of 20:3n9 in plasma, and cats given a safflower oil (SO) diet had higher AA in plasma than cats given the HBF diet, but similar to cats given a SO-tuna oil diet. Male cats given the HBF diet had degeneration of the testes, but the testes of males with SO in the diet were histologically normal, but actual reproductive ability was not tested. Queens given AA-free diets with or without LA did not bear live kittens. When AA was given some of the queens completed a normal pregnancy. The authors concluded that LA met the needs for spermatogenesis, but AA was necessary for female reproduction. Pawlosky et al. (1994) demonstrated Ä6 desaturase activity existed in cats, and the liver and brain cooperate to produce 22:6n-3 and 22:5n-6 when no preformed C20 or C22 precursors were in the diet. Pawlosky and Salem (1996) gave 3 groups of queens diets containing either 1% or 3% corn oil (CO), or 1% CO +AA. There was a high incidence of congenital defects in the kittens from the 1% CO group, 100% viability in the other 2 groups. As the diet containing 3% CO without AA supported reproduction, dietary factors other than AA appeared to be involved. Pawlosky et al (1997) gave corn oil based-diets to queens and was able to maintain 20:4n-6 concentrations in the developing brain and retina of kittens, but only those diets containing 22:6n-3 could support high concentrations of docosahexanoic acid in these tissues. Low concentrations of 22:5n-6 in the brains of COdiet kittens suggested that kittens have a low biosynthetic capacity to produce this fatty acid and 22:6n-3. Electroretinograms of the kittens at 8 wk of age showed adverse changes in the kittens whose maternal diets were devoid of AA and C22:6n-3. Our observations. We gave cats AA-free diets based on partially hydrogenated vegetable fat (% FA: C14:0, 0.2; C16:0, 12.9; C18:0, 11.4; C18:1, 43.3; C18:2, 29.0; C18:3, 2.2). Five male cats that received the vegetable fat diet alone for >2.5 years, were exposed to 12 queens which resulted a mean ± sem of 5.25 ± 0.52 kittens/litter indicating that dietary AA was not necessary for reproduction in toms. Four queens that had the same dietary treatments as the toms came into estrus, mated and gained body weight, but only one successful pregnancy was completed with 3 normal kittens. The other 3 queens had 3, 1 and 1 pregnancies, but produced no viable kittens. Queens ate the majority of these kittens, but the parts found indicated the pregnancy went to full term. Our results support the conclusions of Pawlosky that
reproduction in queens may be impaired not by lack of AA, but long chain n-3 fatty acids.
MacDonald, M. L., Rogers, Q. R. &Morris, J. G. (1983) J. Nutr. 113:1422-1433.
Pawlosky, R., Barnes, A & Salem, N. (1994). J. Lipid Res. 35: 2032-2040.
Pawlosky, R. J. & Salem, N. (1996) J. Nutr. 126: 10881S-1085S.
Pawlosky, R. J. Denkins, Y. Ward, G. & Salem N. (1997) Am J. Clin. Nutr.65:465-472.
Rivers, J. P. W., Sinclair, A. J. & Crawford, M. A. (1975) Nature (Lond.) 279:98-99.
Sinclair, A. J., Slattery, W., McLean J. G. and Monger E. A. (1981) Brit. J. Nutr. 46: 93-96.
Milk fat synthesis and draw down on body fat in the muskox (Ovibos moschatus)R. G. White, W.E. Hauer, R. Kedrowski
Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks AK USA 99775
For ruminants both food supply and body condition can influence milk production and offspring growth and survival. However, there are few studies on the relative balance between de novo synthesis of lipid by the mammary gland from food energy and draw down (i.e. mobilization) of lipid from body fat to meet milk energy output. Since milk energy output scales allometrically with maternal body weight, it would appear that meeting energy requirements of the offspring is under strong adaptive regulation. For ruminants in Arctic systems food availability and quality as well as body fat reserves can vary annually, and often both can be scarce at parturition. Since body fat is used at higher efficiency than food metabolizable energy for both milk-lipid synthesis and also as the energy source to drive milk-protein synthesis, body fat mobilization may be more tightly regulated before food becomes dependably available. We measured milk intake by muskox calves with the 3HOH/ 2HOH technique (Holleman et al., 1975), determined in vivo maternal body fat from the body water pool size (White et al., 1989) and assayed [3H] in milk lipids to determine the fraction of milk fat derived from the body water pool: a measure of de novo synthesis by the mammary gland (Assumptions: [H] in milk fat = 0.132 g/g, 53 % of H in newly synthesized fatty acid was derived from body water, Jungas 1968). All cows were grazing, and a high plane (HP) treatment involved supplementation with a high protein (18 %CP) pelleted ration given to half the group. For both high and low plane (LP) combined, mean specific activity ratio [3H]fat-H/ [3H]water-H was 0.39, indicating 74 % of milk lipid was synthesized de novo (range 57 % at wk 1-2 to 85% at wk 22). Initial output of milk fat was 150 g/d; it peaked on wk 4 at 170 g/d and declined linearly to <70 g/d at wk 22. Natural weaning occurred at approx. wk 32, but extended lactation into a 2nd y was frequently observed. Based on HP-LP differences, supplementary feed stimulated output of milk fat until wk 4-6 but was without effect at and after wk 8 of lactation. During wks 1-2 intake of the supplement was associated with a higher lipid mobilization (20 g/d) than de novo synthesis (5 g/d), but by wk 4 the reverse was noted; de novo synthesis (21g/d) exceeded lipid mobilization (9 g/d). By wk 8 no effect on de novo synthesis or mobilization was attributable to the supplement. An energy balance sheet for mammary lipid dynamics suggests that to drive increases in de novo synthesis of milk fat at 4 wk lactation, daily intake of high quality food would need to increase by 0.63 kg (14 g/kg0.75 for a muskox weighing 160 kg) over maintenance intake. The results lend theory to reports for sheep, reindeer and caribou that a green flush of food at or just after the time of parturition results in a higher rate of gain in offspring nursing from fat rather than thin females. It remains to be discovered if the change in importance between de novo synthesis and lipid mobilization that occurs during the 1st 4 wks of lactation is regulated or if it is responding stoichiometrically to current nutritional influences.
Holleman D.F. et al., 1975. J Dairy Sci 58: 1814-1821. Jungas R.L., 1968. Biochemistry 7: 3708-3717.
White R.G., 1989. Can J Zool 67: 1125-1133.
Measuring nutrient intakes of free-ranging animalsStuart A. Altmann
Department of Ecology & Evolutionary Biology, Princeton University, Princeton NJ 08544 USA
I describe a method for obtaining quantitative estimates of the intakes of nutrients, toxins, or other food components during foraging by free-ranging animals. I consider food components not only in the conventional sense of chemical compounds, such as riboflavin or oxalic acid, or classes of components, such as proteins or lipids, but also in a more general sense to include those properties--such as energy content, cost, foraging time, predation risk, and so forth--whose intakes are linear functions either of the amounts of various foods that are ingested or of the amounts of time required to do so.
Intakes are estimated either as the mean amount of a given component taken in per day (the daily intake) or as the rate of its intake as a function of elapsed time in foraging bouts devoted to it (the food-specific intake rate). To estimate mean daily intake of a nutrient or other food component, a factorial method is used, in which the number of grams of a given food component that are obtained from each food is obtained from the product of that foods mean values for its time budget, unit intake rate, unit mass, and composition. In turn, each of these factors is broken down into smaller factors that can be estimated from data that are obtainable under field conditions.
As byproducts of this method, one also obtains estimates of mean values for other salient characteristics of foraging, such as the fraction of potential feeding time spent eating a given food, as well as the number of units or of grams of that food consumed per day or per meal on that food, or per elapsed minute in bouts of feeding on it. The applicability of this method has been demonstrated in several recent studies of foraging behavior in the baboons of Amboseli National Park, Kenya; for further details, see Altmann (1991, 1998), Altmann & Shopland (2002).
Altmann, S. A. 1991. Diets of yearling primates (Papio cynocephalus) predict lifetime fitness. Proc. Natl. Acad. Sci., USA, 88:420-423.
Altmann, S.A. 1998. Foraging for Survival: Yearling Baboons in Africa. Chicago, University of Chicago Press, 609 p.
Altmann, S. A. & J. M. Shopland. 2002. Do baboons time feeding interruptions optimally? (in prep.)
Different dietary fat sources on broiler performanceA. Haghnazar1, G. Rahimi2
1Animal Sciences Research Institute, Sari, Iran 2Dept. of Animal Sciences, Mazandaran University, Sari, Iran
The purpose of the present experiment was to compare the effects of dietary fish oil (South Caspian Sprat oil (Clupeonella grimmi)( and poultry fat supplementation on growth performance of broiler chickens. One thousand 1-d-old broiler chicks from a commercial line (Hybro breed) were obtained from a local hatchery. Broiler chicks randomly distributed into five experimental groups (five treatment Ø five replication) with 40 birds/replicate). Chicks were given one of the five experimental diets containing 3 or 6% South Caspian Sprat oil, 3 or 6% poultry fat and a control group with no fat diet. Wood shavings were used as litter and the lighting regimen provided 23 h of light per 24 h throughout the rearing period. Water and food were provided ad libitum. Temperature was set at 34°C during the first wk and gradually reduced by 2°C per wk down to 22°C. Broiler chickens were fed a basal diet containing 3000 kcal ME/Kg and 19% crude protein. The control diet was supplied for all experimental groups from the 1st day till two wk of age, but from 2 wk of age onwards, the treatment groups received the supplemented diets. At 2, 4 and 6 wk of age, live body weight was obtained on a pen basis, and feed intake per pen was recorded for the previous biweekly period. Mortality was recorded daily. At 6 wk of age, 10 birds of each experimental group were killed by cutting the jugular vein and abdominal fat were dissected and weighed. At 2 wk of age, broilers fed control diet during the starter period (1 to 2 wk) no significant differences in weight gain were found between experimental groups. At 6 wk of age, broilers fed poultry fat treated diet, realized the highest body weight gain, but these was significant (P<0.05) only in comparison with birds fed diet with 6% fish oil. During the starter period (1 to 2 wk) no significant differences in feed intake were found between experimental groups. But cumulative feed intake averaged lower (P<0.05) for chickens fed diet with 6% fish oil compared to other dietary groups. Cumulative feed conversion (kg feed intake per kg body weight gain) did not differ among treatments. Abdominal fat pad weight were significantly (P<0.05) increased in chickens fed diet treated with poultry fat. In conclusion, the results of this experiment indicate that broiler diet supplemented with 3% fish oil (Clupeonella grimmi) is associated with a reduction in abdominal fat deposition and also had no adverse effect on growth performance. Furthermore, using moderate amount of fish oil in broiler diet may causes a change in the fatty acid composition of deposited fat in favor of unsaturated fatty acids.
Fatty acid composition of plasma and red cells in a group of captive asian (Elephas maximus) and African (Loxodonta africana) elephantsM. Clauss1, Y. Wang2, K. Ghebremeskel2, W.J. Streich3, C. Lendl4
1Institute of Animal Physiology, Physiological Chemistry and Animal Nutrition, Veterinaerstr. 13, 80539 Munich, Germany
2Institute of Brain Chemistry and Human Nutrition, University of North London, UK
3 Institute of Zoo Biology and Wildlife Research (IZW) Berlin, Germany
4Veterinary Clinic Dres. Erben, Fitz and Partners, Gessertshausen, Germany
When wild animals are brought into or kept in captivity, the result is generally a reduction in the content of polyunsaturated fatty acids (PUFA) and an increase in the n-6:n-3 fatty acid ratio. In theory, these shifts could have consequences on a variety of body functions. We investigated, for the first time, the FA composition of plasma and red blood cells of captive elephants, using a group of four Asian and two African female, adult animals. All animals originated from the same facility and received the same diet.
A comparison with data on free-ranging or camp elephants showed that the captive animals had lower proportions of PUFA, and for several lipid fractions a higher n-6:n-3 ratio. The difference in PUFA content seemed to be less drastic in African than in Asian elephants, suggesting that free-ranging African elephants might face situations of marginal PUFA supply, as previously proposed in the literature. The pattern found by other researchers in a small sample of elephant spermatozoa, that captive Asian elephants tend to have lower levels of n-3 and total unsaturated FA, prevailed in our small sample as well. In our case, differences due to diferent dietary regimes are unlikely. Reported differences in digestive strategy between the elephant species might account for this observed discrepancy. Among the potential consequences of a low PUFA provision, the viability of sperm for artificial insemination practices, warrants particular attention in the future.